- UMass policy is to allow a combination of 2nd level enumeration (without repeating the captions) as long as no gap exists within the combination. ​ **Example:​** ​ 1990:​no.4-1990:​no.7,​ 1990:​no.10-1995 //can be written as:// 1990:​no.4-7,​ 1990:​no.10-1995. ​

- UMass policy is to allow a combination of 2nd level enumeration (without repeating the captions) as long as no gap exists within the combination. ​ **Example:​** ​ 1990:​no.4-1990:​no.7,​ 1990:​no.10-1995 //can be written as:// 1990:​no.4-7,​ 1990:​no.10-1995. ​

- Exception: ​ More than one gap exists in a volume'​s 2nd level enumeration,​ but not if adjoining the preceding or following volume in the statement. ​ **Example:​** ​ 1990:​no.4-5,​ 1990:​no.7-8,​ 1990:​no.10-1995 //can be written as// 1990:​no.4-5,​7-8,​1990:​no.10-1995. ​ Combining "4-5, 7-8" makes the statement easier to read.

- Exception: ​ More than one gap exists in a volume'​s 2nd level enumeration,​ but not if adjoining the preceding or following volume in the statement. ​ **Example:​** ​ 1990:​no.4-5,​ 1990:​no.7-8,​ 1990:​no.10-1995 //can be written as// 1990:​no.4-5,​7-8,​1990:​no.10-1995. ​ Combining "4-5, 7-8" makes the statement easier to read.